1. Field of the Invention
The invention relates to a method and apparatus for extracting heat and mechanical energy from a pressured gas by expanding same in a plurality of peripherally spaced cylinders fixedly mounted about the axis of an output shaft which is driven by a unidirectional clutch connected to pistons respectively cooperating with the cylinders.
2. Description of the Prior Art
The great majority of rotary engines designed for operation by a pressured gas have utilized linearly reciprocating pistons and cylinders. Similarly, many expanders have resorted to the use of linearly reciprocating pistons and cylinders. In most instances known to Applicant, the pistons have been connected to a crank shaft and in this manner, the reciprocating movements of all the pistons produced by expansion of a pressured gas in the cylinders is converted into a rotational power output, while the gas is concurrently cooled.
The utilization of a crank shaft inherently involves expensive precision manufacturing operations in order to ensure the balance of the crank shaft. Additionally, the successive power strokes of each piston are delayed by an interval determined by the rotational speed of the crank shaft, since this determines the time required for the piston to return from its bottom dead center position to its top dead center position in its respective cylinder. For this reason, the utilization of fluid pressure engines is primarily confined to low torque, high speed applications. It inherently does not have the ability to generate a substantial torque at low speeds due to the substantial delay in the successive expansions of the pressured gas charges supplied to each cylinder. Additionally, there is the well known deficiency involved in every crank shaft of the effective moment arm of the piston force varying cyclically from zero to a maximum and then back to zero as the piston proceeds through its entire power stroke.